1. Field of the Invention
This invention relates to a hand tool for cutting pipe, particularly copper pipe such as that used in central-heating installations. As used herein, `cutting` includes providing a circumferential groove in the pipe.
2. Prior Art
Various forms of hand tools for cutting pipe are known, such pipe cutters generally having a rotatably mounted cutting wheel for engaging, in use, one side of the pipe, which is supported at its opposite side by a pair of spaced rollers.
In one form, the pipe cutter is adjustable to enable a range of different diameter pipes to be cut. This is accomplished by providing screw or other means for effecting relative adjustment movement between the cutting wheel and the rollers. Once a size of pipe is clamped tightly between the cutting wheel and the rollers, cutting is carried out by relative rotation between the tool and the pipe, normally by rotating the tool around a fixed pipe. PCT Specification No. WO90/05610 shows adjustable pipe cutters of this form, one of which has the cutting wheel axle fixed in one body part which is hinged to a second body part. The two body parts are urged together by a strong compression spring acting between them.
European Patent specification No. 0204802 B discloses a further form of pipe cutter designed for cutting a particular size of pipe. The device has a rotatable cutting wheel mounted on a shaft which is movable in one direction along an arcuate track when a pipe is inserted into a central hole of the device through an entry slot. After insertion the wheel snaps forward so that the pipe is held in engagement with a pair of spaced rollers at one of its sides, and with the cutting wheel at its opposite side. Thereafter relative rotation in one direction between the tool and the pipe causes the wheel to rotate and bite into the pipe as the cutting wheel shaft rotates and moves along the arcuate track in the opposite direction to its movement on pipe insertion. During such movement, the shaft presses against, and is pressed inwards by, strip springs which define part of the arcuate track. Continued relative rotation effects cutting of the pipe. Whilst this cutter is generally satisfactory in use, it is relatively expensive to produce.